An Eeveelution (Japanese: ブイズVuis) is a popular term used among fans for the current group of seven Pokémon that evolve from Eevee. It is a portmanteau of the words "Eevee" and "evolution". Its definition may be extended to include Eevee itself. The term eventually passed into the realm of official usage first as a pun in the official guide of Pokémon Stadium 2[1], and then later in the TCG Theme DeckEeveelution, as well as in the game Pokémon Ranger: Shadows of Almia. A full set of Eevee's evolutions is popular among collectors.

In the games

Generation I

In Generation I, the Eevee obtained at the Celadon Mansion could easily become a helpful partner to the player's own starter Pokémon, especially considering the high Special stat of 110 shared by the three then-known evolutions, and the ability to cover for the weaknesses of the starters' final forms. With relatively few Pokémon of each respective type available until late in the games, Jolteon, Flareon, and Vaporeon were a staple to complete the game.

One may notice that only Eevee and its evolved forms from Generation I have the distinctive ruff-like collar. The Eeveelutions released afterward do not possess this feature. Likewise, all Eeveelutions from this generation evolve via exposing Eevee to an evolutionary stone, unlike future generations.

Vaporeon

Vaporeon, the first of the Eeveelutions in National Pokédex order, is a Water-type Pokémon. Like most other Pokémon of its type, its highest stat is its HP. Evolving from an Eevee that is exposed to a Water Stone, Vaporeon now has the ability to use the HM move Surf, among other powerful Water-type moves, to take down its foes. This is particularly advantageous, considering its relatively high Special stat (and later Special Attack stat) of 110.

Among Vaporeon's special abilities are the moves Acid Armor, which raises its low Defense stats, and the lesser-known Aurora Beam, which lowers the opponent's Attack. Vaporeon's Water Absorb also helps it by recovering HP any time it is hit by a Water-type attack.

Jolteon

Jolteon is the second of the Eeveelutions, and is an Electric-type Pokémon. Much like Vaporeon exemplifies the Water type's generally high HP, Jolteon exhibits its type's extraordinary Speed. Like Vaporeon, its Special Attack (formerly Special) is its second-highest stat, making it a good choice as an Electric type in games prior to Generation IV.

Like Vaporeon, Jolteon has an Ability that heals it when it is hit by attacks of its own type, Volt Absorb, as well as several moves that are rare and nearly exclusive to it. Among these is Pin Missile, a move once praised as the best way to take down a Psychic type in Generation I.

Flareon

The final member of Generation I's Eeveelution trio is Flareon, a Fire-type Pokémon, evolving from Eevee when it is exposed to a Fire Stone. Flareon's highest stat is its Attack. However, this high Attack is not without its drawbacks: many of the moves that Flareon learns are special moves, and since, unlike Vaporeon and Jolteon, Flareon fell on the other side of the Special split, its formerly formidable Special became its Special Defense; its Special Attack is somewhat lower. In addition, it learns only two physical STAB moves, Fire Fang and Flame Charge, both of which have moderately low power.

However, its Ability, Flash Fire, gives it a great boost if a Fire-type move is used on it. The ability to resist against the mostly-Special Water type's powerful moves also gives it a slight advantage.

Generation II

The addition of two additional evolutions in Generation II did much to boost Eevee's popularity, as well as give it a reputation of continued versatility. With yet another Eevee available relatively early on in the game, the new evolutions of Espeon and Umbreon were easily obtained; in fact, it now became possible, even, to get multiple Eevee with just one game, rather than requiring at least two coordinated games to get all three evolutions as was the case in Generation I, due to the introduction of breeding.

Generation II Eeveelutions are obtained when Eevee is leveled up with high friendship at certain times of the day. Due to this, and the lack of a clock in certain Generation III games, Eevee cannot evolve into Espeon or Umbreon in Pokémon FireRed and LeafGreen. Each of the Kimono Girls now owns one Eeveelution.

Espeon

As a Psychic type, Espeon is well-known for a common trait among Pokémon which share its type: a rather high Special Attack and somewhat high Speed. It also has high Special Defense, another common trait among Psychic types. Taking advantage of the time and friendship features introduced in Generation II, Espeon evolves from Eevee when it is raised to maximum friendship and gains a level during the daytime.

Umbreon

Umbreon is the second of the two Generation II Eeveelutions, a Dark-type Pokémon. Somewhat uniquely, it was the only pure Dark-type in the generation it was introduced in, and also uniquely, is the only Eeveelution better suited to defending rather than attacking. With its two highest stats in Special Defense and Defense, respectively, and its two lowest in the respective offensive stats, Umbreon is much more often used to cause status problems than damage. Umbreon evolves from Eevee when it gains a level during the nighttime with maximum friendship.

Like Espeon, Umbreon has the Ability Synchronize, causing other Pokémon that attempt to use its defensive, status-causing strategy against it to suffer as well. As a Dark type, it is also the only Eeveelution whose type has an immunity (to the Psychic type). It, alongside Espeon, is the starter Pokémon for Pokémon Colosseum.

Leafeon

A Pokémon often theorized and hoped for over the history of the franchise, Leafeon, was finally the realization of the Grass-type evolution of Eevee. Like Flareon, Leafeon has a relatively high Attack stat, however, its strongest stat is in Defense. Unlike Flareon, it has a diverse movepool, with the rare Leaf Blade counted among its STAB moves. As with the Generation II Eeveelutions, Leafeon takes on a new manner of evolution: when an Eevee is leveled up where a large, mossy rock lies, it will evolve into this Pokémon.

Leafeon has the Abilities Leaf Guard and Chlorophyll. Teamed up with a Flareon, which also gets bonuses from sunnyweather, these Abilities can be used advantageously, despite the vulnerability to a Fire-type move.

Glaceon

Glaceon is an Ice-type evolution of Eevee. Like Espeon, its highest stat is its Special Attack; however, unlike Espeon, it has a higher defense, a common trait among other Ice types. Similarly to Flareon's problem with physical moves, it has a relatively small movepool to work with regarding special moves. Glaceon evolves from Eevee when it is leveled up where an ice-covered rock lies.

Like Leafeon, Glaceon's special Abilities, Snow Cloak and Ice Body, has to do with the weather, making it more evasive in hailstorms or healing during them. It is the only Eeveelution to learn one of the two countering moves, with Mirror Coat being one of its moves.

Cynthia's Glaceon

Virgil's Team

Virgil owns an Eevee and every one of its final forms. They debuted together in BW102 where he used them in his mountain rescue duties. He also used them to fight through the Higaki Conference, which he won.

Included with the Skyridge expansion, also, is a Theme Deck by the name of Eeveelution, which features the original three Eeveelutions as the focus. However, the deck only includes the three Generation I Eeveelutions: whereas Umbreon was released in the set, Espeon was not.

There have also been several deck archetypes that revolve around the Eeveelutions, mostly due to their versatility and their lack of a unanimous weakness. One of the most recent is Eeveelutions, which utilizes Pokémon-ex variants of all five then-known Eeveelutions. The use of this archetype has been assisted by the release of a great many Energy cards that provide more than one type of Energy, such as Rainbow Energy. In Majestic Dawn, Glaceon and Leafeon were introduced to the TCG, as well as including all previous Eeveelutions. The most recent expansion to include the Eevee family is Undaunted, including all but Glaceon.

Vaporeon is the only Eeveelution that does not share any weakness with another. Flareon and Jolteon are weak to Ground-type moves, Espeon, Umbreon and Leafeon are weak to Bug-type moves, Umbreon and Glaceon are weak to Fighting-type moves, and Leafeon and Glaceon are weak to Fire-type moves.

Flareon is the only Eeveelution who has a type advantage over more than one other Eeveelution (being Leafeon and Glaceon).

Espeon is the only Eeveelution not to have a type advantage over another at all (Vaporeon is strong against Flareon, Jolteon is strong against Vaporeon, Flareon is strong against both Leafeon and Glaceon, Umbreon is strong against Espeon, Leafeon is strong against Vaporeon and Glaceon is strong against Leafeon).